Mod-Your-151 How-To Guide

[Bluewelders]

You might try a 200uf capacitor on the motor to slow it down, 100uf might not be enough.

[Hobweld]

Does anyone know if the pcb for the astro 130 is a pwm or a scr board
Ken

[Bluewelders]

If the Daytona mig is the same board, it looks like an SCR board.
The component with the three legs and the metal tab on the back may be labeled SCR or THY if it is.

[sirhannick]

Please do not make posts about other welders like Astro, Daytona, or others. It's called thread hijacking and is poor forum etiquette. If you have responses which are about other welders or separate subjects, please start your own thread. Thanks.

[4x4_ranger]

I have an extra 100000uf 60vdc cap $45 if some one would like to use it to mod there welder.

[spiderx]

Thanks Bluewelders for posting this up. I bought a HF Mig 151 last year and am only a hobbist welder. I already had to claim my warranty on the second unit as the wire feed mechanism died out on me. The first one I bought had a DOA wire feed mech.
So onto my third unit with a 2 year warranty now.
I search to see if anyone did any type of mods for the feed motor and found this amazing thread.
I noticed the fan on this third one doesnt sound as quite as the first two. Kinda made me wonder if it was supplying enough air flow and if it was a defective fan. I was having doubts till now. Im a going to try these mods out.
Can anyone recommend what gauge wire to use for a replacement on the ground feed?
Anyone have a list of the current parts used?
I have copied down some stuff reading thru the 11 pages but would like to see a list of stuff needed to copy paste and print out so i can take it to the local electronics store.
I dont have much knowledge with electronic purchasing. But can follow instructions well.

[Bluewelders]

"I noticed the fan on this third one doesnt sound as quite as the first two. Kinda made me wonder if it was supplying enough air flow and if it was a defective fan."

They are sort of a defective fan when they are new.
You need to get a 120mm 230v fan that puts out at least 100cfm.
Like a EC1238A2HBT.
If you shop around you may find something similar for cheaps.

This list is pretty reasonable
http://weldingweb.com/showpost.php?p...3&postcount=29
Just make sure that the components you use are the same or higher voltage rating.
The work clamp cable on them used to be about a 6ga so I suppose a 4ga would fit and work.

The output capacitor will have a little over 50V on it, so 60v-70v would be fine.
You need 60,000uf or so,you could use a couple 33,000 to get the capacitance high enough, if you use multiple capacitors.

[sirhannick]

Originally Posted by spiderx

Anyone have a list of the current parts used?
I have copied down some stuff reading thru the 11 pages but would like to see a list of stuff needed to copy paste and print out so i can take it to the local electronics store.

You might have to buy a lot of the stuff online as most local parts stores (ie Radio Shack) no longer carry a very large variety of components. Here's a list of what I was able to find on Radio Shack's website:
-50 Ohm, 10W Resistors - http://www.radioshack.com/product/in...ductId=2062292 (closes thing radio shack sells to what was used in this thread)
-4A, 400V Rectifier - http://www.radioshack.com/product/in...ductId=2062582 (Exact component used in my circuit)
-100 uF, 50V Capacitor - http://www.radioshack.com/product/in...ductId=2103625 (could also use the 35V variant)

Just because it's on their website does not mean it is in every store. They will, however, ship it to the store for free I believe. Radio Shack's prices are not the best by far, there are many other online sources such as:
Digikey
Allied Electronics
Newark
Jameco
& More

[sirhannick]

Assuming you order from Digikey, here is a selection of components:
1, 565-3332-ND, CAP 100000UF 80V ELECT SCREW TER, GIANT CAPACITOR, $36.88
http://search.digikey.com/scripts/Dk...client_id=5042

1, 565-1321-ND, CAP 100UF 35V ELECT KMG RAD, MOTOR CAPACITOR, $0.35
http://search.digikey.com/scripts/Dk...client_id=5042

1, KBL04-E4/51GI-ND, RECTIFIER BRIDGE 4A 400V KBL, RECTIFIER, $0.99
http://search.digikey.com/scripts/Dk...client_id=5042

1, KAL25FB50R0-ND, RES 50 OHM 25W 1% ALUM WW, BLEED RESISTOR, $3.30
http://search.digikey.com/scripts/Dk...client_id=5042

1, P12898-ND, FAN AC AXIAL 230V 119X38 3100RPM, COOLING FAN, $15.58
http://search.digikey.com/scripts/Dk...client_id=5042

Subtotal $57.10

I hope that helps. Took me a while to compile. You can pick a different fan, but pay attention to CFM (air flow) & decibels (noise).

[spiderx]

Thanks for posting that.
I have a other local electronics store in a nearby city. They have been a very good source in the past for some stuff I needed. But they usually require the info to see if they have it LOL!.
Their prices are a bit steep at times but all depends on what it is.

Im not against online buying at all either, just not sure if I am jotting everything down correctly and will find exactly what these guys used. 11 pages of info is kinda hard to graps all that was used. I know I copied all that Bluewelders posted in the first page. But then ppl are asking will this fan work and stating they cant find stuff in stock. So I figured I would ask yas.
Again, thank u for posting those links. Im going to call R.S. and the local electronic store and see what they have and what kind of prices versus online.
Anyone know if you can you a computer case fan? I was thinking it wouldnt be enough voltage but cant remember what it states. Ill have to open my pc case up or call the pc store and see if they carry a 120mm 230v 50/60hz fan. Just a thought that up.

[Bluewelders]

Computer case fans are 12v, they don't put out the volume of a 230v fan.

[sirhannick]

Originally Posted by Bluewelders

Computer case fans are 12v, they don't put out the volume of a 230v fan.

Not entirely true. Computer fans are 12V. They do and can push enough air (250 CFM: http://www.newegg.com/Product/Produc...82E16835706015). They are available in a tremendous variety of sizes, powers, qualities, and sweet sweet glowing colors! BUT they would have to be run off of an AC->DC adapter. Their would be a power loss in the adapter making them far less efficient than the equivalent 220V fan. So for the simplest hook-up use a 220V fan.

[sirhannick]

P.S. I don't mean to be rude or sound rude. I'm just "emotional" and make posts in various states of mind. So just ignore my moodyness.

[TexasWeld]

Originally Posted by sirhannick

Assuming you order from Digikey, here is a selection of components:
1, 565-3332-ND, CAP 100000UF 80V ELECT SCREW TER, GIANT CAPACITOR, $36.88
http://search.digikey.com/scripts/Dk...client_id=5042

1, 565-1321-ND, CAP 100UF 35V ELECT KMG RAD, MOTOR CAPACITOR, $0.35
http://search.digikey.com/scripts/Dk...client_id=5042

1, KBL04-E4/51GI-ND, RECTIFIER BRIDGE 4A 400V KBL, RECTIFIER, $0.99
http://search.digikey.com/scripts/Dk...client_id=5042

1, KAL25FB50R0-ND, RES 50 OHM 25W 1% ALUM WW, BLEED RESISTOR, $3.30
http://search.digikey.com/scripts/Dk...client_id=5042

1, P12898-ND, FAN AC AXIAL 230V 119X38 3100RPM, COOLING FAN, $15.58
http://search.digikey.com/scripts/Dk...client_id=5042

Subtotal $57.10

Will these parts work correctly?
Has this configuration been thoroughly tested?




Hello gentlemen,

My knowledge of electronics is limited so I'm looking to mobes, bluewelders, ect to provide me with solid information. I know this upgrade was a bit experimental at first.. so will the above list of parts work?

I am going to buy a brand new Harbor Freight 120 amp Dual Mig 151 and immediately after I verify it is not DOA I want to mod it.
Will the welder function correctly if I install the parts listed in the above list?

Shouldn't the wires going to the capacitor be about 6 gauge?
And what effect does it have when going from a 60v cap to a 80v cap?

I'll be doing this to a brand new welder and I want to do it right the very first time, so I would REALLY appreciate some assistance. If you can tell me what connectors, best solder, and any little pieces I should acquire before getting started I would be grateful.

Thanks very much!

[Bluewelders]

The parts you listed look correct.
You may end up needing a 200uf capacitor instead of a 100uf capacitor, depending on your personal preferences.
Going from a 60v cap to a 80v cap should slightly improve reliability in the long run,but no real difference,the max voltage on them is about 52v.

10ga stranded wire is fine for the capacitor wires.
Between the duty cycle and the shape of the waveform, they really don't carry as much power as you would think.

[TexasWeld]

Thanks!
Can you share some insight on the 200uf vs 100uf cap?
Preference on feed?
What will each cap do?

[Bluewelders]

The capacitor mod will make the wire feed motor run faster than it needs to.
The 100uf capacitor will slow the feed motor,200uf will slow it more .
Most people seem to think the 100uf will go to a low enough speed.

[TexasWeld]

Which one is closest to factory speed?
I don't want to hotrod it, just want to make it function more efficiently

[Bluewelders]

Been too long since I ran mine with the original circuit,one of the people who has recently done the changes would be better to ask.

[thermalking]

bump00

[bright]

Modded a HF 94164. 110A dual mig
Wow - did the 100000ufd cap, second rectifier, fan and 100ufd on the motor - it's cooler and a better arc
and better speed control! What a glorified power supply!!! Thanks to Bluewelders for the guide. Oh, the PWM board is the same as the 151. The huge cap (3" in diameter) is mounted in the space between the wire spool and the polarity terminals, with an insulated through hole for the cap wires back to the rectifier. The space between the choke and the rectifier is only 2" Thxs again!!!

[Bluewelders]

Glad you like it.
The first time you use it after the mods is kind of a shock.
The arc is smooth and quiet, and there is a lot of leeway in the settings, that will still make a decent weld.
It really makes them a lot better.

[86gnx turbo]

New to the forum looking to do the mods myself. Just thought i would give the digi-key P/N for the cap holding bracket 338-1366-ND hope that helps someone else. Thanks Glen

[serious_lee]

Here's a different setup I am trying out. The rectifier is a 200 Amp model intended for windmills and it wouldn't fit in the original location. Capacitor is 63,000 uF 63V.

Everett

http://i127.photobucket.com/albums/p...s/100_1276.jpg

[Bluewelders]

I sometimes wish the case was a little bigger.
Does your welder work better ?